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AI phone agents in Vietnamese

ThunderPhone supports Vietnamese across the product: agents can speak and understand Vietnamese on calls, the dashboard ships with a Vietnamese interface, and the docs site has a dedicated Vietnamese edition.

Vietnamese is one of ThunderPhone's 47 supported voice languages, with eight compatible voices in the current catalog.

Vietnamese voice availability and pricing

The current catalog includes eight voices that support Vietnamese:

  • six multilingual voices; and
  • two premium Vietnamese voices, Lien and Minh.

Vietnamese uses a premium language path at +3¢ per minute, which applies to all of its compatible voices. That makes the engine-plus-language rate:

  • Spark: 2¢ + 3¢ = 5¢/minute
  • Bolt: 5¢ + 3¢ = 8¢/minute
  • Storm: 9¢ + 3¢ = 12¢/minute

These illustrative figures exclude telephony and other optional charges. The agent builder shows the current all-in rate as settings change.

Vietnamese is a tonal language, so evaluate candidate voices against real calls: personal names, street addresses, phone numbers, English loanwords, and the mix of Vietnamese and English your callers actually use.

Vietnamese in the dashboard and documentation

Vietnamese is a shipped dashboard locale, not just a call setting. A team can configure prompts, review calls, and manage the organization entirely in the Vietnamese interface.

ThunderPhone also publishes a dedicated Vietnamese documentation edition on its docs site, giving Vietnamese-speaking builders localized product guidance alongside the Vietnamese caller experience.

Vietnamese and English in one call

An agent has one primary language and can have additional languages. If Vietnamese is primary and English is additional—or the reverse—the agent can switch automatically when the caller changes language mid-call.

The selected voice must support every configured language. Test realistic switch points before going live—callers often give email addresses, product names, or technical terms in English even when the rest of the call is in Vietnamese.

Sample Vietnamese call experience

The following flow is written in English to describe what happens, not to prescribe exact translated wording.

Agent starts in Vietnamese: Greets the caller, identifies the business, and asks how it can help.

Caller answers in Vietnamese: Says they want to check the status of an order.

Agent continues in Vietnamese: Confirms the caller's name, looks up the approved order-status action, and reads back the current status.

Caller switches to English: "Can you send the tracking link to my work email?"

Agent switches to English: Repeats the email address back and confirms where the link will be sent.

Caller returns to Vietnamese: Asks when the package will arrive.

Agent returns to Vietnamese: Answers from the approved data and offers further help before ending the call.

The switch happens within the same call; the caller never hangs up, presses a phone-tree option, or dials a separate number.

Build and test a Vietnamese agent

  1. Set Vietnamese as the primary language, or add it as an additional language.
  2. Choose one of the eight voices that supports the complete selected language set.
  3. Confirm the displayed +3¢ per-minute language rate in the builder.
  4. Write the operating prompt in the language your team can review most reliably, and attach only approved knowledge and integrations.
  5. Run browser tests and simulations with Vietnamese-only, English-only, and mixed-language scenarios.
  6. Review transcripts, pronunciation, tool actions, and escalation behavior before deployment.

Frequently asked questions

Does ThunderPhone support Vietnamese voice calls?

Yes. Vietnamese is one of ThunderPhone's 47 supported voice languages and currently has eight compatible voices in the catalog.

How much does Vietnamese cost?

Vietnamese adds 3¢ per minute to the selected engine rate. The engine-plus-language rate is therefore 5¢ on Spark, 8¢ on Bolt, or 12¢ on Storm, before telephony and other optional charges.

Are premium Vietnamese voices available?

Yes. The catalog currently lists two premium Vietnamese voices, Lien and Minh, alongside six multilingual Vietnamese-compatible voices. All eight use the same +3¢ premium language path.

Is the ThunderPhone dashboard available in Vietnamese?

Yes. Vietnamese is a shipped dashboard locale, so builders can use the product interface in Vietnamese.

Are ThunderPhone docs available in Vietnamese?

Yes. ThunderPhone publishes a dedicated Vietnamese documentation edition on its docs site.

Can a Vietnamese agent switch to English during a call?

Yes. Add English as an additional language and select a voice that supports both. The agent can switch automatically when the caller changes language mid-call.